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Guitorque
Ha! I finally managed to dredge up one of the things I filed away to be posted later. I really have Got to start writing stuff down... | |
Torque wrenches only allow for a certain amount of tension before they will torque no more. Guitar strings need a certain amount of tension to remain in tune. I propose that the tuning pegs themselves could be miniature torque wrenches with a central control to manually change overall pitch.
Anyone
could tune any guitar instantly just by turning all of the pegs until they began clicking.
Tronical tune
https://www.youtube...watch?v=cfOreJ29r0U Clever [bhumphrys, Oct 17 2018]
[link]
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The resonant frequency of a string is dependant on the mass, tension, and length. By changing the length - using the tuning pegs - the tension and hence the resonance can be varied. |
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But the untensioned length of the string is also temperature-dependant. |
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Thus, the tension for a given resonance varies; a constant-tension device would be possible but would not deliver consistent note tuning. |
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This sort of plays to a limited audience...get it [fried]?
hahaha |
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The guitar neck will expand and contract as the
temperature and humidity change, too. |
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Experienced musicians know that you should always bring
your instruments into the venue and let them acclimatise
for a while before trying to tune and play them. |
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That explains where I've been going wrong, [Wrong]. The
harpsichord in the northeast breakfast room has only been
there since about 1820, and whenever I play it, it sounds
ghastly. |
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Oh and [+] for a brilliant idea let down only by practicalities. |
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The clear solution is to have set torque levels for the temperature
and humidity level thermostats... |
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You play the harpsichord yourself? How frightfully common of you. |
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Assuming the strings are made of steel, a set of very
powerful magnets on cantilevers should do the trick. |
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//You play the harpsichord yourself? // It's a turn of phrase.
As in "The seventh Earl built the Orangery and landscaped the
village". |
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The pegs could be mounted in a frame of brass and steel, arranged so that their different expansions with temperature precisely compensates for the changing string length. |
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Alternatively the strings could be wound from invar, an alloy specifically designed to be stable with temperature. |
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With enough effort, everything can be compensated for. You could even mount a tiny metal bellows, like they had in early bomb computers, to compensate for ambient air pressure. However after a point it might just be easier to stick an electric motor on each peg, add a microphone and have a battery-powered auto tuning system. |
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We ought to be able to devise a purely mechanical autotuning
guitar. I'm thinking of clockwork mechanism that will measure
a precise interval of time (eg, 1 second), coupled with a very
delicate escapement driven by the vibration of the string.
The mechanism can therefore determine how many vibrations
occur in 1 second, and this in turn can be used to either
tighten or loosen the string by a small amount before the
process is repeated, iteratively. |
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Another approach might be for the guitar to have some reference resonators (i.e. a row of tuning forks) one of which would be activated at the same time as the string is plucked. Then you'd use the beat frequency formed by the superposition of the two to drive the tuning mechanism. |
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I'm willing to learn otherwise, but I'd have judged that the
effect of tension on pitch far outweighed the effect of
length. Considering an infinitely stiff string and neck, a
fractional increase in string length (say half a millimetre)
will have negligible effect on the free length of about a
metre on the guitar, but will cause the tension to drop
precipitously. For a real case where both the string and the
neck act as springs, the effect on tension will be less
marked, but I bet it's still dominant. |
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Guitar strings don't vibrate at a specific, well-defined
frequency during normal playing. The player's left hand sees
to that. |
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The frets don't help you out here, either, because the player
will often bend the strings sideways slightly to play slightly
higher notes. |
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String pitch depends on length, mass per unit length, and tension, as [8th] correctly but quite wrongly pointed out. |
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The sounding length is the distance from the two fixed points the string bears against; this is fixed by the frame of the instrument and does not change except through structural distortion of the instrument frame (e.g. due to humidity or temperature). |
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Turning the tuning pins only affects the tension, and so therefore this invention would actually work just fine, so long as the torsion mechanism was sufficiently finely set. I suspect that would be the main challenge to actually producing such a device. |
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Thinking about weighing scales, there are spring scales and there are balances. Spring scales would work the same as a torsion wrench, using the springiness of a spring as a reference force. Balances on the other hand use gravity to provide the fixed reference force |
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Gravity tuners are baked and widely known to exist, in the form of violins mounted horizontally inside early 20th century self-playing Orchestrion machines. The violin strings are attached to weighted levers, and are tuned by adjusting the weights on the levers. Then, the tension is constant no matter the temperature, humidity etc. |
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Obviously this system does not compensate for the length changing due to flex or distortion of the instrument frame, or for the mass per unit length changing (e.g from dust accretion, or corrosion), but should be pretty effective. |
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//String pitch depends on length, mass per unit length, and tension// - and velocity as well; Guitars travelling close to the speed of light will increase in mass due to relativistic effects, which will affect the pitch of the note from the (now heavier) strings. |
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<Engages impulse drive and accelerates to 0.5 C> |
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<Strums sequence of power chords> |
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You're right ... the mass increases, and the guitar is compressed along the axis of travel. |
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// correctly but quite wrongly // |
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I already said it depends on mass, and I already suggested dust accretion as one way the mass might increase. There's not that much difference between dust accretion and acceleration to near light speed. |
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We've long suspected that James Dyson is up to something sinister... he has that smug "Ah, Mister Bond, I've been expecting you" look. |
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This has to be worth using in shower conditions for guitarists
who sing in the shower |
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and required like autotune for singers. |
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I really wanted to create the Gitoque but it was a total flop. |
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+ because I think mini torque wrenches would be so cute, but
I misread the title thinking it was some kind of guillotine
made from a guitar! guitarotine |
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